Industrial hygiene in the workplace current topics of interest

Transcription

1 UTC Environment, Health & Safety group EH&S European Regional Conference October, 2016 Amsterdam, Netherlands. Industrial hygiene in the workplace current topics of interest Sean Mahar, PhD, CIH, CSP, PE Euro Safety and Health

2 Industrial hygiene in the workplace current topics of interest Sean Mahar, PhD, CIH, CSP, PE Euro Safety and Health Sean Mahar Contact Details Euro Safety and Health UK Phone: 44 (1743) UK Mobile: Introduction The industrial hygiene (IH) program has several facets and chemicals and noise are the usual suspects but the recent introduction of the Physical Agents (Electromagnetic Fields) Directive has increased interest in this often overlooked topic. Educational Objectives This presentation is intended to act as an introduction to better understand the common chemical, noise and EMF risks in UTC workspaces and the techniques to evaluate them to maximize the value of IH consultants. The Plan Industrial hygiene and its role Common issues at UTC sites Metalworking fluids Modern solvents Chromium Ventilation The EMF Directive 1

3 the recognition, Industrial Hygiene evaluation, and control of hazards from work that may result in injury, illness, or affect the well being of workers. Assessments Qualitative evaluations primarily address hazard Quantitative evaluations primarily address risk Hazards Chemical Solvents, dusts, acids, metals, etc. Physical Noise, vibration, lighting, electromagnetic radiation, ergonomics Biological Animals and by products, mold, endotoxins Hazard and Risk Hazard is the potential to cause harm Risk is the likelihood of harm occurring Routes of Entry Inhalation Ingestion Skin Inhalation particularly important exposure important due to lung surface area Occupational Exposure Limits (OELs) A concentration in parts per million (ppm) or in milligrams or micrograms per cubic meter of air (mg/m 3 or µg/m 3 ). Not safe/unsafe limits but aimed at protecting most workers. Some people could still be affected. 2

4 OELs Short-term limits can be 15 or 20 minute average or a ceiling level substances that can cause their effect in a short time, such as irritants, or for substances that can have very serious effects. Long term limits usually an 8 hour average normally substances that exert a long term or cumulative effect OEL Sources European Union - Indicative Occupational Exposure Values (IOELVs) UK Workplace Exposure Limits (WELs) US Occupational Health and Safety Administration (OSHA) - Permissible Exposure Limits (PELs) American Conference of Governmental Industrial Hygienists (ACGIH) - Threshold Limit Values (TLVs ) Other OELs American Industrial Hygiene Association (AIHA) Workplace Environmental Exposure Levels (WEELs) Bundesministerium für Arbeit (BMA) Maximale Arbeitsplatzkonzentration (MAKs) NIOSH Recommended Exposure Limits (RELs) Metalworking Fluids Evolved over time to current water based fluids Dermatitis traditionally a concern Some machinists suffer from airways sensitization with asthma or alveolitis Microbial growth and byproducts such as endotoxins thought to be culprit NIOSH REL 0.5 mg/m 3 Ventilation Machine mix HEPA filter stops particulates Delay in opening allows mist to clear 3

5 A Puzzle MDEA A sticky amber film forming on vertical surfaces, most notable on stainless steel fridges and wire grids Sample scrapings sent to 2 labs for analysis who both identified it as MDEA, n-methyldiethanolamine n-methyldiethanolamine CAS Water soluble BP, 760 mm Hg, C VP, 20 C, <0.01 mm Hg R36 Irritating to eyes Metalworking Fluid Another Fluid 40% MBM n,n'-dimorpholinomethane CAS Water soluble BP, 760 mm Hg, C VP, 20 C, <0.01 mm Hg H314: Causes severe skin burns and eye damage H317: May cause an allergic skin reaction H350: May cause cancer H341: Suspected of causing genetic defects Modern Solvents In the old days we had benzene With cancer concerns Then trike With ozone depletion concerns Also with cancer concerns Now a revolving door of substitutes 4

6 n-propyl Bromide 1-bromopropane n-pb CAS Degreaser and cleaner Swansolv Ensolv n-propyl Bromide American Conference of Governmental Industrial Hygienists (ACGIH) - Threshold Limit Value (TLV ) 10 parts per million (ppm) in ppm in 2014 irritation and nervous system damage n-propyl Bromide trans-1,2-dichloroethylene Largely being replaced by trans-1,2-dichloroethylene trans DCE t-dce CAS Degreaser and cleaner Novec Vertrel C-HD trans-1,2-dichloroethylene Chromium USA, UK, Germany have 200 ppm limits irritation eyes, respiratory system; central nervous system depression 5

7 Chromium Exists in different oxidation states: 0 (elemental metal, Cr), +3 (trivalent, CrIII), and +6 (hexavalent, CrIV) Elemental and trivalent have a TLV of 0.5 mg/m 3 (500 µg/m 3 ) due to respiratory and skin irritation, dermatitis concerns Chromium (VI) Hexavalent Chromium is also a carcinogen the TLV is 50 µg/m 3, for soluble compounds like sodium chromate (chromic acid) the TLV is 10 µg/m 3, for insoluble compounds like barium chromate the TLV is 0.5 µg/m 3, for strontium chromate Local Exhaust Ventilation (LEV) Air Flow Stack Duct Air Flow Fan Air cleaner Hood Paint Booth Problems Inadequate flow: ACGIH Ventilation Manual (good practice) recommends 0.5 m/s Bad design: Flow in booth causes dead spots and counter currents Protective Flow Protective Flow 6

8 Useless Flow Poor Evaluation 0.5 m/s 0.5 m/s here, not here Physical Agents Directives Vibration 2002/44/EC Noise 2003/10/EC Artificial Optical Radiation 2006/25/EC Electromagnetic Fields 2013/35/EU Electromagnetic Fields Directive Addresses: Direct effects Indirect effect Does not address longterm effects Directive at risk workers with active implanted medical devices (AIMD) with passive implanted medical devices containing metal with body-worn medical devices Pregnant workers Electromagnetic Fields Directive Requires: Risk assessment Sets: Exposure Limit Values ELVs Exposure Action Values EAVs 7

9 Electromagnetic Fields Directive Risk Assessment can drive: Worker information instruction and training Controls Medical surveillance EMF Risk Assessment Identify possible sources Check manufacturer data Measure if needed Model if needed Implement controls if needed Electromagnetic Spectrum EMF Sources Low Frequency Electric welding and melting High current or voltage (>500A, >200 kv) Induction heaters Magnetisers/demagnetisers Electric crack detection EMF Sources High Frequency Communications antennas Industrial heating and drying RF plasma (chem vapor deposition, sputtering) RF welding EMF Hazards Effects vary depending on field High frequency fields Low Frequency fields Static fields 8

10 High Frequency (100 khz 300 GHz) Tissue heating Specific energy Absorption Rate (SAR) 100 khz-10 MHz limb heating, induced E 10 MHz-400 MHz whole-body heating 400 MHz-10 GHz: localized heating 10 GHz-300 GHz: surface heating Low Frequency (1 Hz 100 khz) Electric fields cause surface charge: induction of current density and electric fields within body Magnetic fields penetrate body: induction of current density and electric within body Adverse health effects: Cognitive impairment, nerve stimulation Electric fields Static Fields Electrostatic discharge to grounded objects Magnetic fields Movement in a static field Vertigo, Nausea, Metallic taste Magneto-phosphenes (flashes before eyes) Problems with metallic implants, projectiles, medical devices Hierarchy of Control PPE Administer Engineer Substitute Eliminate EMF Controls Change equipment or process Shielding, interlocks Barriers, signage Personal protection clothing, meters and alarms 9

11 Wave Parameters Wavelength Frequency Velocity Distance Peak to peak Trough to trough Units Meters (km to nm) Symbol is λ Wavelength Periodicity Cycle completion Units Cycles/second Herz (Hz) Symbol is f Frequency Speed of Light 3 x 10 8 m/s Symbol is c sometimes ν Velocity 10

12 Relationship λ = c/f λ = wavelength (m) f = frequency (Hz) c = velocity (m/s) Voltage Electrical pressure Potential to do work Volts Current Movement of charge Amperes Produced by Voltage Volts/meter Symbol is E Electric Fields Magnetic Fields E and H Produced by current Amps/meter Symbol is H 11

13 Free space impedance E/H = 377Ω E and H relate PD = r E Power density PD = Power density (mwatts/cm 2 ) E = Electric Field (volts/meter) H = Magnetic Field (amps/meter) r H Inverse Square Law Inverse square law I I = incident energy d = distance 2 d1 = I 2 1 d2 12

14 Measurement Electric Field Magnetic Field SAR E or H Measurement Detector Pickup Readout Electric Field Measurement Pickup small antenna or dipole Detector diode or thermal sensor Magnetic Field Measurement Pickup small loop or dipole Detector diode or thermal sensor 13

15 LF Measurement ETM-1 Meter for Static Magnetic Fields Measurement range: 0 Hz, up to 2 Tesla Properties: For magnetic field, with isotropic Hall probe, automatic and manual selection of measurement range HF Measurement EMR-200 / EMR-300 Highfrequency radiation meters High-frequency Survey System with interchangeable E and H field probes Specific Absorption Rate (SAR) Time rate of energy absorbed in an incremental mass, divided by that mass. Average SAR in a body is the time rate of the total energy absorbed divided by the total mass of the body. watts per kilogram (W/kg) SAR Measurement measure the E-field inside the body measure temperature change use differential power method 14